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gwilliamson
24-03-2008, 09:56 PM
I wonder if anyone has had any experience of this?

I have been contacted this weekend by a customer that we installed a 5kw Fujitsu WM inverter for last summer.
His exact description is a strange high pitched whistling noise coming from the outdoor unit both when the system is running and when off. The system itself is working fine ,just seems to be producing this strange noise. I am going to pop in on wednesday to investigate but wondered if any of you had come accross this before??

Many thanks

Gareth

nike123
24-03-2008, 10:27 PM
It is probably faulty electrolytic condenser of power inverter.

Brian_UK
24-03-2008, 11:20 PM
Or, is it the sound of gas passing through a restrictor of some sort?

nike123
24-03-2008, 11:45 PM
Or, is it the sound of gas passing through a restrictor of some sort?
If AC doesn't cool or heat, then there is no flow of refrigerant.;)

gwilliamson
25-03-2008, 12:14 AM
Apparently all is working fine so i dont expect a leak. This is a constant whistle noise so i am thinking it may be electrical??
Thanks

Brian_UK
25-03-2008, 12:36 AM
If AC doesn't cool or heat, then there is no flow of refrigerant.;)But it could be equalizing :cool:

nike123
25-03-2008, 12:51 AM
But it could be equalizing :cool:

Of course that it could be!:D:D

paul_h
25-03-2008, 04:26 AM
If it happens when the unit isn't running, it's usually the inverter power filter board or capacitors.

Larry2
25-03-2008, 04:41 AM
Does the noise stop when you shut off the mains? Magnetic cores, such as in switching power supplies can vibrate at their operating frequency. This happens when windings and core are not cemented in place during manufacturing. These assemblies are typically dipped or doped to prevent motion. Ceramic capacitors can also make noise in switch mode supplies.

declan simmonds
25-03-2008, 11:25 AM
hello mate i would check inside the condenser as it sounds like its coming from there but maybe it might be the condenser fan motor is it the same pitch all the time? does it change in heating mode ? ive had a few fan motors on dakin inverter units making a whistling noise changed the fan motor and it stopped freaky
declan

nike123
25-03-2008, 11:40 AM
hello mate i would check inside the condenser as it sounds like its coming from there but maybe it might be the condenser fan motor is it the same pitch all the time? does it change in heating mode ? ive had a few fan motors on dakin inverter units making a whistling noise changed the fan motor and it stopped freaky
declan

Hi, Declan

If you read carefully first post, you maybe found this sentence very interesting:;)


His exact description is a strange high pitched whistling noise coming from the outdoor unit both when the system is running and when off.So, where is the connection between fan noise and supposed fact (supposed because that is customer words) that this noise is heard when system is off?

declan simmonds
25-03-2008, 11:48 AM
oh in that case it must be the power inverter board humming duh ill get me coat

Frostycold
25-03-2008, 01:55 PM
Hi Guys
You have noise wether running or not & the unit runs ok. Maybe it's the wind whistling through the condenser.

Frostycold

nike123
25-03-2008, 02:15 PM
Hi Guys
You have noise wether running or not & the unit runs ok. Maybe it's the wind whistling through the condenser.

Frostycold

What if day is without wind?:rolleyes:

Danny11
25-03-2008, 02:36 PM
Hi pal

Iv had the same thing,Mine was a tiny hole on top of the compressor check that. but it could also be equalizing.

Daikin=Overated
26-03-2008, 09:23 PM
Im pretty convinced this is just the perfectly normal operating sound related to an inverter drive. "It's a high pitched noise"........yeah that's the noise inverters make. "It's running perfectly-yeah that's because it's not broken".

I fitted one last year, and was quite suprised at how noisy the Fujitsu's were on full song when. There a vast improvement on a fixed speed system in terms of noise emmission, but they still leave a lot to be desired especially if fitted in residential environments. That whining noise will do your head in.

Theres no easier way (as someones suggested) than to isolate the supply to the outdoor unit-it should fade out over 20 seconds say.

Finally-tell the client to stop there winging and pay the call out:D

Tell us what your findings were hey?...............

nike123
26-03-2008, 10:00 PM
Guys, read the description of problem more carefully. Half of these post would not existed if the original post is carefully read.

gwilliamson
26-03-2008, 10:48 PM
Well guys, thanks for all your help.
Attended the site today to investigate the whistling noise and guess.. No noise what so ever. Ran the system in heating and cooling running absolutely fine. Switched off and still no noise.....
Bloody customers!!!!!!
All temps are fine and run amps etc.

I'm so glad i drove all the way to that one!!!!!
Thanks anyway.